Understanding the behavior of shoppers in a retail store may be useful to producers and suppliers of the products on the display shelves, and may also be useful to the retail store owners who would like to maximize sales. Purchases may be a function of how many shoppers pass though a particular region, or zone of the store, and may also be a function of how much time a shopper spends within a zone. The actions of shoppers while in a particular zone may also be useful, for example, whether or not a shopper just passes through a zone; whether or not a shopper picks up and/or inspects a product; and/or whether or not, a shopper places a product in a shopping cart. How many of each of these actions takes place within a particular zone may also be useful information. Efforts to understand shopper behavior may include observation and note taking by shopper auditors, or electronic tracking. However, the note taking method can be inaccurate and cumbersome, and the electronic tracking method may be complex and expensive, thereby frustrating efforts to simply, accurately, and inexpensively collect information about shopper behavior.